Incandescent wire arrangement in audions



Ja'n. 5, 1932. s, o w 1,839,323

INCANDESCENT WIRE ARRANGEMENT -IN AUDIONS Filed Feb; 19, 1929 2 She-ts-Sheet 1 170". J.

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I Jnren/ar Jan. 5, 1932. s. LOEWE 1,839,323

INCANDESCENT WIRE ARRANGEMENT IN AUDIONS Filed Feb. 19, 1929 2 Sheets-Sheet 2 Patented Jan. 5, 1932 .UNITED STATES PATE roFmcE 'SIEGMUND LOEWE, 0F BERLIN, GERMANY monn'nnscnn'r WIREARRANGEMENT 11v minions As the incandescent wires in audions considerably expand under the influence of heating during operation, the possibility arises of their being bent. This possibilityis particularly strong if the filaments are exposed to mechanical vibration of the valve.- The bends frequently are not constant but variable and as a consequence vibrations of the filament take place which may cause disthe amplification factor(espec1ally the electrostatic action of the anode through the grid upon the cathode) may undergo a periodical variation. In this mannerthe amplification factor varies with the frequency and disturbing amplitude-oscillations of the plate current and plate voltage respectively occur which more particularly lead to disagreeable interfering noises if they possess the period of an audible .frequency. j

These disturbances are by themselves not changed if, as is frequently done,v two filaments are laidoutin parallel. Fig. .6 shows one of the known arrangements consisting of an incandescent wire 1 whose leads 2 and 3 are on the same side of the electrode sys-. temwhilst on the other side it is borne and strained inthe middle by a support 4, so that two filament stretches 1 and 1" run inside the electrode system acute-angl'ed to one another. V y p The invention consists in restricting in a possibilities of movement and expansion towards one another 1n such a manner that the either altogether prevented or considerably reduced in their-amplitude or may occur only in such direction thatthey do not cause disturbances. My invention may be best understood with reference to the accompanying drawings.

Fig. 1 shows a cross-sectionby an electron discharge device with the incandescent wire arrangement according to my invention.

turbances; as an example the reciprocal'of.

particular manner several filaments in theirinterfering oscillations'above described are Application filed February 19, 1929, Serial No. 341,143, and in Germany February 22, 1928 Fig. 2 shows the way of manufacturing the incandescent wire arrangement of Fig. 1

Fig. 3 shows a modification of the incandes cent wire arrangement, of 1 in a larger scale, the manufacturing of which is illustrated in Fig. 4. V p

A further modification of mechanical means for tightening the incandescent wires is illustrated in Fig.5. I Fig. 6 shows as above mentioned the known arrangement having disadvantages to be avoided according tov my invention, particularly to the arrangement of Fig. Fig. 7 is a modification of m device in side elevation.

Fig. 8 shows a modification of the filaments inside of the electrode system.

Figs. 911 relate to incandescent wire: ar-

rangements with more than 2 filaments.

Fig. 1 shows an especially simple embodiment of an arrangement of two incandescent wires where the possibilities of oscillation are limited according to the invention. For this purpose two filaments 1 and 2 need only be laid one above the other in'such a manner that they cross, say, at the central point 5. "In I the course of manufacture this is appropriately done in sucha manner that two-wiresare first laid out in parallel at which according to Fig. 2 the supporting wires 3 and 4. are arranged in the same directions and that, in order to 'efiect the arrangement accordingjito Fig. 1, one of these supporting wires, for instance wire 4, is turned by 360' or appropriately somewhat more. There isn'o objection to producing the arrangement'in such amanner that both supporting wires 3 and 4. lie at the different sides of the parallel filaments 1 and 2 and that one of the supporting wires is turned by fully 180 so that the wires are interlaced. i

- The electron discharge device oflFig. 1 is in 6., the plate 7,.the bulb 8, the socket 9. 1

Awirearrangement as showninFigs; 1

a well known manner completed bythe grid and 3 respectively is no longer in a position to carry out lateral oscillations even if the filaments expand very strongly; the possibility of deflection and oscillation within the area drawn more particularly has been limited or even made impossible. Such arrangements of filaments are particularly suitable for such arrangements of electrodes in which a defiection in a certain direction does not exercise a disturbing influence. Fig. 8 shows such an arrangement consisting of parallel level anode plates 10 and 11 and grids 12 and 13 where'the common plane of the filaments 1 and 2 is vertical to the anode planes. Even if such an arrangement should still carry out oscillations parallel to the anodes 10 and 11 in the direction of the double arrow, this would not effect a change in the reciprocal of the amplification factor-of the electrode system. The disturbances above described therefore could "not occur notwithstanding any oscillations of the filament.

The form of construction according to Fig. 3 appears to be the simplest for-the mutual stifl'eni'ng arrangement of two filaments. It may happen, however, that such arrangements have electrical drawbacks of another nature. In many cases an unfavourable influence might be exerted on the course of the valve characteristic if according to Figs. 1 and 3 respectively the central point of the filaments, constructed as a junction, would have a larger distance from the other elec trodes than the-other parts. If that is to be avoided, a clasp 14 may in the manner shown in Fig. 5 be laid round the middle portion of filaments 1 and 2 in order thus to connect the same. 3

Figs; 1 and 5 relate to leads of the filament voltage-in which the" full difference of volt age exists between the right ends of the filament and the left ends so thatthe middle point 5 according to the invention lies simultaneously for the two filaments at the same potentialeven i-f the filament voltage switched on is'not constant, but an alternating voltage; j If,however,inth'e manner shown in Fig. 6", the full filament voltage lies between neighbouring ends of the filaments, a con ductive connection of the middle points of the" filaments would lead to disturbances of the desired course of the current. In filament arrangements in which middle points of the filaments which are lying opposite one another, do not possess the same potential, it is advisable according to the further subject of the invention, to arrange sepanators,v either by a small tube or disc of insu lating material 15 being according to Fig. 7

- laid! between. the filaments which otherwise,

accordingto Figs. 1 and 3 are interlaced, or jointed by theclasp-lt ofFi'g. 5.

The fmthersubject of the invention relates to filament arrangements which even in the case of electrodes of any shape not only neutralize such vibrations, but fully avoid the same.

For this purpose more than two incandescent wires are used, for instance three incandescent wires interlacing in similar man ner as the two filaments of Figs. 1, 3, 5, 8, 7. In that case there is in no direction as essential possibility of the filament bending through and therefore of a disturbing oscillation.

Figs. 9 and 10 illustrate an exemplary embodiment of the further subject of the invention. In order to make the matter plainer only three filaments. are used though the invention may not only be applied also, but may even be better-realized if a larger number of filaments is used. In Fig. 9 three filaments 16, 17,18 are strained; inaparallel and clamped together by a clasp 19 in order that they may not deflect'sidewise. In Fig. 10 the three incandescent wires 16, 1'? and 1-8 meet at a junction 5. This may be accomplished, for instance, by the incandescent wires being first held parallel to one-anotherwhereat'the points for fixing the'three filamentsappropriately lie on each side at thecorners of an equilateral triangle 20-and 21 so that the two equilateral triangles run in-para'llel planes to one another. If, n'oW,-oneof thetwo t riangles is within its plane tu.rned sufliciently wide round its centre, appropriately by 180 or more, the filaments touch one another" or upon further turning interlace. In" Fig. 10 the angle of rotation is 360. Such stabilized filament arrangement cannot bebent through in any direction with the normally appearing forces.

If more than three filaments are usedi't is also advisable to fix the ends' of the filaments to the corners of a regular polygon, in order that for reasons of symmetry no direction is preferred for a deflection'or'ben'ding.

Fig. ll'shows a cross-section of a filament arrangement according to-Fig. '9- or 10 with cylindrical grid 22 and anode 23.

With the use, too, of more than 2-"incandescent wires it may be advisable tointerpose insulations between the'wireswhose con-- tact points lie at different potentials;

An arrangement, moveover, where. only a small number (say 2-) of filaments are-used, may be given the bending stabilityof an arrangement with a larger number ofincandescent wires by using wires with non-circularcross-section in order that the moment of inertia of the wire cross-section is largest in the direction in which a'certainpossibility of defiection'still exists. 7

If, according to the forms o-fconstruction of Figs. 5 and? special substances are arranged between the filaments, for instance-in the shape of the, connecting clasp 17 or ,a disc or small plate 15-of'insulatingmaterial, it is advisable according to the further sub order to produce a mechanic crossing of said filaments.

2. Method for manufacturing incandescent cathode arrangements in an electron discharge device using three filaments hav ing a common crossing point, which consists in arranging the single filaments in parallel, in connecting the corresponding ends of said filaments by means of metallic conductors, and in turning one of said metallic conducments, in supplying each polygon with a leading-in wire for the heating current..

7. In an electron discharge device an incandescent cathode arrangement consisting of several filaments having a commoncross-' ing point, of regular polygons ,of conductive material at which the ends of said filaments are fastened, of leading-in wires of said cathode arrangements attached at said regu V I lar polygons, of a grid, of an anode, and of leading wires of said electrodes.

In testimony whereof I have afiixed my signature.

SIEGMUND LOEWE.

tors in order to produce a mechanic crossing l of said filaments.

3. Method for manufacturing incandescent cathode arrangements in an electron discharge device using more than two filaments having a common crossing point, which consists in arranging the single filaments in parallel, in fastening the ends of said filaments in the corners of regular polygons manufactured of conductive material, and in turning one of said polygons in order to produce a mechanic crossing of said filaments.

4.. Method for manufacturing incandescent cathode arrangements in an electron discharge device using three filaments having a common crossing point, which consists in arranging the single filaments in parallel, inv fastening the ends of said filaments in the corners of regular triangles manufactured of conductive material, and in turning one of said triangles in order to produce a mechanic crossing of said filaments.

5. Method for manufacturing incandescent cathode arrangements in an electron dis charge device using three filaments having a common crossing point, which consists in arranging the single filaments in parallel, in fastening the ends of said filaments in the corners of regular triangles of Wire, and in turning one of said triangles in order to produce a mechanic crossing of said filaments.

6. Method for manufacturing incandes cent cathode arrangements in an electron discharge device using more than two filaments 7 having a common crossing point, which consists in arranging the single filaments in parallel, in fastening the ends of said filaments in the corners of regular polygons manufactured of conductive material, and in turning one of said polygons in order to produce a mechanic crossing of said fila- 

